Redis 8.0 Async io-threads & Linux Kernel Tuning (redis.conf)

Supanote Core Team @supanote · 1 min read

plain (ini) 1 day ago · 45 lines · 2 views

Artifact

Verified Blueprint Redis 8.0+

Unlock up to +112% throughput in Redis 8.0 with the redesigned async io-threads engine, lazyfree non-blocking eviction, and active defrag.

✓ Configures Redis 8 redesigned asynchronous network I/O threading without command-execution mutex contention
✓ Eliminates main-thread latency spikes on large DEL/FLUSH/evictions via lazyfree-lazy-* flags
✓ Pairs active memory defragmentation with required Linux vm.overcommit_memory and somaxconn settings

Quick Fetch

# Redis 8.0+ High-Throughput Production Configuration (/etc/redis/redis.conf)
# Prerequisite Linux sysctl (/etc/sysctl.d/99-redis.conf):
#   vm.overcommit_memory = 1
#   net.core.somaxconn = 65535

bind 127.0.0.1 -::1
protected-mode yes
port 6379
tcp-backlog 65535
tcp-keepalive 300
timeout 0

# 1. Redis 8.0 Redesigned Asynchronous Multi-Core I/O Engine
# Offloads socket reads, RESP parsing, and reply writes across cores (set to ~60-75% of physical cores, max 8-12)
io-threads 8

# 2. Memory Ceiling & Non-Blocking Lazy Eviction
maxmemory 16gb
maxmemory-policy allkeys-lfu
maxmemory-samples 10

lazyfree-lazy-eviction yes
lazyfree-lazy-expire yes
lazyfree-lazy-server-del yes
replica-lazy-flush yes
lazyfree-lazy-user-del yes
lazyfree-lazy-user-flush yes

# 3. Online Jemalloc Active Defragmentation (Prevents RSS bloat on variable-sized payloads)
activedefrag yes
active-defrag-ignore-bytes 256mb
active-defrag-threshold-lower 10
active-defrag-threshold-upper 100
active-defrag-cycle-min 1
active-defrag-cycle-max 25

# 4. Hybrid RDB + AOF Persistence & Latency Monitor
appendonly yes
appendfsync everysec
aof-use-rdb-preamble yes
no-appendfsync-on-rewrite yes
latency-monitor-threshold 5
slowlog-log-slower-than 2000
slowlog-max-len 512

1# Redis 8.0+ High-Throughput Production Configuration (/etc/redis/redis.conf)

2# Prerequisite Linux sysctl (/etc/sysctl.d/99-redis.conf):

3# vm.overcommit_memory = 1

4# net.core.somaxconn = 65535

6bind 127.0.0.1 -::1

7protected-mode yes

8port 6379

9tcp-backlog 65535

10tcp-keepalive 300

11timeout 0

13# 1. Redis 8.0 Redesigned Asynchronous Multi-Core I/O Engine

14# Offloads socket reads, RESP parsing, and reply writes across cores (set to ~60-75% of physical cores, max 8-12)